Hearing protective device and method of making the same

ABSTRACT

A hearing device including a foam, a foam insertable portion, a component, and a foam handle portion, and a method of forming the same. The component is nestable with and bondable with the foam such that the component is at least partially within the foam insertable portion and the foam handle portion. The hearing protective device includes earplugs attached to a flexible cord, under-the-chin element, or headband. A method of making a hearing protective device including disposing a component into a mold, introducing a foam or foamable mixture into the mold, causing the foam to rise such that the component is nested within and bonded with the foam.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. patent application Ser. No.09/990,654 filed on Nov. 21, 2001 which claims priority to U.S.Provisional Patent Application Ser. No. 60/253,433 filed on Nov. 28,2000, both of which said applications are herein incorporated byreference in their entirety.

BACKGROUND

The present invention relates generally to hearing protective devices,and more particularly to hearing protective devices including asemi-rigid component.

The use of hearing protective and noise attenuating devices are wellknown, and various types of devices are available for this purpose. Suchdevices include, but are not limited to, earplugs and semi-auraldevices. Foam components are well known for use with these devices,providing both sound attenuation and enhanced comfort for the wearer.

Earplugs are generally preferred for continuous use over longer periodsof time. Foam earplugs composed of resilient polymer foam materials suchas foam rubber or polyurethane are well known in the art. Slow recoveryfoam earplugs, such as those disclosed in U.S. Reissue. No. 29,487 toGardner, Jr., are not only comfortable, but have also been shown todeliver high in-field noise protection at all frequencies. U.S. Pat. No.5,203,352 to Gardner, Jr. also discloses a hearing protective earplugcomprising a polymeric foam.

A hearing protective device may further include a cord that is attachedto a pair of earplugs and extends therebetween. Conventional cords arecommonly designed so that the cord may be permanently attached to theearplugs and more specifically, each end of the cord may be permanentlyattached to stem portions of the respective earplugs.

A typical semi-aural hearing protector assembly generally includes aresilient U-shaped band with holders at opposite ends, and a pair ofinwardly directed ear protectors (“pods”) that are detachably mounted tothe holders. Semi-aural hearing protectors that enter the ear canaloffer hearing protection but are somewhat less comfortable than thosethat simply cap the ear. U.S. Pat. No. 4,461,290 to Gardner, Jr. et al.discloses a semi-aural device incorporating a foam component. U.S. Pat.No. 4,671,265 to Anderson also discloses a semi-aural device.

With respect to these devices, the sound-attenuating (acoustical)component has been made both of flexible, rubber-like materials, and offoam. For earplugs and semi-aural devices, the rubber-like materials areadvantageous because they allow the earplug or device to be directlyinserted into the wearer's ear. However, such earplugs and devicestypically become uncomfortable over long periods of use. Foam earplugsprovide enhanced comfort, but may require rolling down before insertion.

A foam earplug with a stem can provide both the ease of insertion ofrubber-like earplugs and the comfort of foam earplugs. A number ofpatents disclose earplugs having tips or flanges with a relatively stiffstem used to insert and remove the earplug. One earplug, shown in PriorArt FIG. 1, is described in U.S. Pat. No. 5,188,123 to Gardner, hereinincorporated by reference. This earplug includes a circular or ovoidresilient polymeric foam body having a rounded nose end. An elongatedstem is axially embedded in the foam body and extends rearward andaxially therefrom. The earplug may be used in a push-in or roll-downinsertion mode.

While suitable for certain purposes, this prior art earplug requires anadditional manufacturing step over conventional plugs to secure the stemin the foam body. Also, the material of the foam body is prone to peelfrom the insert. In addition, inclusion of a hard stem in the earplugcould be a hazard for the user, the general concern being that potentialinjury could result should the hearing protector become impacted. On theother hand, if the stem is too soft, it tends to buckle upon insertion,limiting the fit of the earplug and reducing the potential usefulness ofthe stem.

Another attempted solution to the above-discussed deficiencies in theart is the use of a porous component as a stem as disclosed in U.S. Pat.No. 5,799,658 to Falco. Therein, individual porous stems aremechanically bonded to the foam during manufacture by controlledpenetration of the foam by the porous component stem. However, theindividual porous stems are relatively expensive and somewhat difficultto manufacture.

Accordingly, there remains a need for a stemmed foam earplug that iseffective in providing hearing protection, yet convenient andcomfortable to use, and has a more efficient and lower cost method ofmanufacture.

SUMMARY

The above discussed and other problems and deficiencies of the prior artare overcome or alleviated by the hearing protective device and methodof manufacture of the invention.

In a preferred embodiment, an earplug comprises a foam and at least onecomponent that is nestable with and bondable with the foam. Thecomponent is disposed at least partially within a foam insertableportion and at least partially within a foam handle portion.

In the preferred method of the present invention, the component isinitially disposed in a mold. A foam or foamable mixture is introducedinto the mold causing the foam to rise and surround the component. Thecomponent is nestable with and bondable with the foam. Also thecomponent is at least partially within a foam insertable portion and atleast partially within a foam handle portion.

In another preferred embodiment, a venting portion is provided in themold. In still another preferred embodiment, a venting portion isprovided on the component. The venting portions allow gas to escape themold during rising of the foam. Further, the venting portions retain thefoam within the mold during rising, thus preventing spillage of the foamoutside the mold. Also, an amount of the foam is permitted to cure inthe venting portion to effectively seal off the mold thus maintaining apressure within in the mold desirable for curing of the foam therein.

The above discussed and other features and advantages of the presentinvention will be appreciated and understood by those skilled in the artfrom the following detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings wherein like elements are numbered alikein the several FIGURES:

FIG. 1 is a conventional earplug;

FIG. 2 is an elevational view of an earplug, according to one embodimentof the invention;

FIG. 3 is a cross-sectional view of the earplug of FIG. 2;

FIG. 4 is an end view of the earplug of FIG. 2;

FIG. 5 is a cross-sectional view of the earplug of FIG. 2 in anotherembodiment;

FIG. 6 is a cross-sectional view of the earplug of FIG. 2 in anotherembodiment;

FIG. 7 is a cross-sectional view of the earplug of FIG. 2 in anotherembodiment;

FIG. 8 is a cross-sectional view of the earplug of FIG. 2 in anotherembodiment;

FIG. 9 is a perspective view of a set of corded earplugs;

FIG. 10 is a perspective view of foam components and a semi-rigidheadband for a semi-aural device;

FIG. 11 is a cross-sectional view of one embodiment of a mold forforming the earplug of FIG. 2;

FIG. 12 is a top view of the mold of FIG. 11;

FIG. 13A is an elevational view of one embodiment of a component stem ofthe earplug of FIG. 2;

FIG. 13B is an elevational view of another embodiment of the componentstem of FIG. 13A;

FIG. 13C is an elevational view of another embodiment of the componentstem of FIG. 13A;

FIGS. 14A-14B are various views of another embodiment of a mold upperportion of FIG. 11;

FIGS. 15A-15B are various views of another embodiment of the mold upperportion of FIG. 11;

FIGS. 16A-16B are various views of another embodiment of the mold upperportion of FIG. 11; and

FIGS. 17A-17H show one embodiment of a method for manufacturing theearplug of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The device and method of manufacture of the invention comprises a foamand at least one component nestable with and bondable with the foam anda method of forming the same.

Referring now to FIGS. 2 and 3, in a preferred embodiment, a uniformfoam earplug 10 comprises a foam insertable portion 12 and a foam handleportion 16. The foam substantially surrounds, encapsulates, or isnestable with and bondable with a component 14 having an embeddedportion 18 with a tip 20. The embedded portion refers herein to thatpart of the component that is at least partially located within, and isbonded to, the foam insertable portion 12 and the foam handle portion16. The foam handle portion 16 has a smaller diameter than the foaminsertable portion 12. A depression 22, illustrated in FIG. 2 as alongitudinal groove, may extend within the foam handle portion 16 atleast partially along the component 14. As is preferred, the earplug hasa flange configuration 13. Alternate depressions (or a lack ofdepressions) and alternative earplug configurations are of coursecontemplated by the invention.

Referring now to FIG. 4, an end view of the exemplary earplug 10 isillustrated. The component 14 is disposed within the foam handle portion16. As is illustrated by this embodiment, depressions 22 (fourlongitudinal grooves are shown) extend at least partially through thefoam handle portion 16 and at least partially along a portion of thecomponent 14.

Referring now to FIGS. 5-8, the preferred embodiments of the presentinvention are shown. Each figure illustrates a foam insertable portion12, a flange 13, a component 14, a foam handle portion 16, an embeddedportion 18, and a tip 20. FIG. 5 illustrates a bullet-shaped earplug.FIG. 6 illustrates a bell-shaped earplug. FIG. 7 illustrates acone-shaped earplug. FIG. 8 illustrates a mushroom-shaped earplug.

The foam handle portions of two earplugs may be each attached to the endof a cord, an under-the-chin device, or a headband by bonding methodsknown in the art. Turning now to FIG. 9, a preferred embodiment includesrespective earplugs 32, 34 that are each attached to respective ends 36,38 of a cord of a device, shown generally at 30. FIG. 9 illustrates thefoam insertable portion 12, the flange 13, the foam handle portion 16,and the longitudinal groove 22. The figure also illustrates theattachment of the cord ends 36, 38 to a passageway within the component14 (e.g. a hollow component) of the earplugs.

Other means of cord attachment are contemplated, including attachment toat least one depression 22, to an exterior of the foam handle portion16, and to an end of the component 14 (e.g., a solid component), amongothers.

The attachment of the earplugs 32, 34 to cord ends 36, 38 may occur byany known method in the art, but is preferably performed thermally,ultrasonically, or by crimping. Where the earplug and the cord materialsare dissimilar, or where such materials do not form a strong bond underthermal or ultrasonic conditions, adhesives may additionally oralternatively be used.

Referring now to FIG. 10, a semi-aural device 40 is shown includingearplugs 42, 44 attached to an under the chin device or headbandcomponent 45. The earplugs 42, 44 are each at least partially attachedto respective ends 46, 48 of the headband 45. FIG. 10 illustrates theattachment of the earplugs 42, 44 to the headband ends 46, 48. Thefigure also illustrates the foam insertable portion 12, the flange 13,the component 14, the foam handle portion 16, and a longitudinal groove22. The earplugs may attach to the headband by any method known in theart. The attachment method provides for the ability to remove theearplugs for replacement or cleaning.

Referring again to FIGS. 2-4, preferably, the component 14 is used as astem of the earplug 10. As such, the component 14 should be rigid enoughto aid insertion into the wearer

s ear, yet soft and pliable enough to be comfortable and safe for thewearer. The semi-rigid component 14 should be selected of a materialthat is compatible with the foam of the insertable portion 12 andcreates a bond between the component and the foam. Thus, the material ispreferably a plastic material, but other embodiments may include paper,dense paper, rubber, foam, stiff foam, porous foam, relatively orsemi-stiff foam, cardboard, or combinations thereof. The preferredcomponent 14 can have disposed within at least one passage, such thatthe component 14 is hollow. Other passages (i.e. voids or relief cuts)are also contemplated for the component. The component 14 may also be ofa solid or dense construction, and may include at least one passage. Thecomponent may also have disposed therein at least one indentation, dipor dimple.

Additionally, the component 14 may be of a different color than the foamof the earplug 10, such that the color of the component 14 is visiblethrough the one or more depressions 22 that may be formed in the handleportion 16, thus clearly distinguishing the handle portion 16 of theearplug 10 for ease in inserting, removing, and otherwise identifyingthe earplug 10. The depression 22 may be in the form of longitudinalgrooves, relief cuts, letters or designs, or the like. An earplug 10with a hollow component 14 may be manufactured such that components of areceiver, or other communication devices, may be attached to the earplugfor communication purposes.

Suitable foams for use with the earplug 10 include those foams known inthe art to be appropriate for use with foam earplugs or other foamcomponents for hearing protective devices. For example, such foams mayinclude soft, pliable self-rising foams with instant recovery. Suitablefoams may also include polyurethane or acrylic blend foams with slowrecovery. Other foams include PVC, silicone, and nitrile, among others.A suitable foam is described in U.S. Pat. No. 5,792,998 to Gardner, Jr.et al., herein incorporated by reference. The earplug described thereinis comprised of a dynamically stiff foam material having a low staticstiffness, and a high dynamic stiffness. Another suitable foam isdescribed in U.S. Pat. No. 4,158,087 to Wood, herein incorporated byreference.

In a method of manufacturing the earplug 10 of FIGS. 1-8, the component14 is disposed, suspended, or placed into a cavity of an earplug mold. Afoam or a foamable mixture is introduced into the mold, and caused torise. Rising may be accomplished by any suitable means, for example byusing a self-rising foam. As the foam rises, it at least partiallysurrounds, encapsulates, or is nestable with and bondable with, or bondsto, the component. Molding may be performed with any suitable moldingprocess and device such as is known in the art.

An earplug mold 50, as shown in FIG. 11, includes a mold lower portion52 and a mold upper portion 54.

The mold lower portion 52 is made of a rigid, non-porous material, forexample, a polymeric material such as polypropylene or high-densitypolyethylene. Also, the mold lower portion 52 may be made of a metalsuch as aluminum. The mold lower portion 52 includes a lower cavity 56for receiving and shaping a foam or foamable mixture 53 to form the foaminsertable portion 12 of the earplug 10.

The mold upper portion 54 of the earplug mold 50 is made of a flexiblematerial, for example, thermoplastic rubber, thermoset rubber, etc., andincludes an upper cavity 58 for receiving and retaining the component 14during manufacture of the earplug 10 and for receiving and shaping therising foam 53, as discussed herein. In one embodiment, the component 14is retained in the mold upper portion 54 by ribs 60 disposed in thecavity 58. In one embodiment, the ribs 60 include four flanges whichproject inwardly into the cavity 58 and traverse the cavity 58 in alongitudinal direction thereof.

To manufacture the earplug 10, the foam 53 is disposed in the mold lowercavity 56. The component 14, particularly shown in FIG. 13A, is insertedin the upper portion 54 such that the component 14 contacts the ribs 60and is thus retained within the cavity 58. The mold upper portion 54 ispositioned proximate the mold lower portion. The cavity 56 communicablyengages the cavity 58. The foam 53 is allowed to rise from the cavity 56into the cavity 58 and to encapsulate the component A bond is formedbetween the foam 53 and the encapsulated component 14. The foam isshaped by the lower and upper mold portions 52, 54, the foam 53 isallowed to cure, and then the foam 53 and component 14 are ejected fromthe mold 50 as the earplug 10.

In another embodiment, the component 14 includes component venting means62, as shown in FIGS. 13B and 13C, to allow for a gas to escape from themold cavities 56, 58 during manufacture of the earplug 10. Specifically,the component venting means 62 allows for gas to escape the cavitiesduring the foaming process, that is, during rising and rising of thefoam within the mold 50. The vented gas includes air originally presentwithin the mold prior to the foaming process and any gas that may beevolved during the process.

The component venting means 62, in one embodiment, includes screwthreads 64 disposed helically about the component 14. The screw threads64 contact the mold upper portion 54 in the upper cavity 58 at least ata top end 66 of the mold upper portion 54. The contact of the screwthreads 64 with the mold upper portion 54 forms vent passages therebetween which allow passage of gas during the foaming process. That is,vent passages are delimited by the screw threads 64 and a surface of thetop end 66 of the upper mold portion 54 forming the upper mold cavity58. The component 14 having screw threads 64 extends from the uppercavity 58 such that the vent passages traverse from the upper cavity 58to an exterior of the of the mold upper portion 54. Thus, the ventpassages allow gas to travel from the cavities 56, 58 to the exterior ofthe mold 50 during the foaming process. More specifically, as thefoaming process commences, the foam begins to rise and occupy anincreased volume of the mold cavities 56, 58, thus increasing thepressure within the cavities 56, 58. Due to this increased pressure, airresiding within the mold cavities 56, 58 prior to commencement of thefoaming process is forced out of the mold cavities 56, 58 through thevent passageways to an exterior of the mold 50.

The component venting means 62, in another embodiment, includes knurls68, as shown in FIG. 13C. The knurls 68 are protrusions formed along thelength of the component 14 which extend radially therefrom. When thecomponent 14 having knurls 68 is inserted in the mold upper portion 54,the knurls 68 contact the mold upper portion 54 to form vent passagewaystherebetween. That is, the vent passageways are delimited by the knurls68 and the surface of the top end 66 of the upper mold portion 54forming the upper mold cavity 58. The vent passageways permit gas totravel from the cavities 56, 68 to the exterior of the mold 50 duringthe foaming process similarly as discussed above with reference to thescrew threads 64.

The screw threads 64 and the knurls 68, in one embodiment, are formedalong the length of the component 14. In another embodiment, the screwthreads 64 and the knurls 68 are formed only at a top end 70 of thecomponent 14. In still another embodiment, the screw threads 64 andknurls 68 are formed only at a confined portion located somewherebetween respective ends of the component 14, for example, at a midpointbetween the respective ends. The top end 70 of the component 14 contactsthe top end 66 of the mold upper portion 54 when the component 14 isinserted in the mold upper portion 54 during the manufacture of theearplug 10.

Size and spacing of the screw threads 64 and the knurls 68 arepredetermined to allow a certain volume of gas to pass through the ventpassageways when a certain pressure accumulates in the cavities 56, 58during the foaming process. Further, the screw threads 64 and the knurls68 are designed to prevent passage of the rising foam 53 from thecavities 56, 58 to the exterior of the mold thus preserving theintegrity of the mold 50 and reducing waste during the molding process.

Additionally, the screw threads 64 and the knurls 68 allow a certainvolume of the rising foam 53 to enter the vent passageways and curetherein effectively sealing off the mold cavities 56, 58 from theexterior of the mold 50. That is, after the excess air within the moldcavities 56, 58 is vented, the rising foam 53 is permitted to fill thevent passageways and to cure therein. More specifically, the rising foamis directed through the vent passageways which act in this instanceessentially as a tortuous path to shear a portion of the foam causingthe foam to collapse and/or densify and cure therein to seal off thevent passageways. This sealing effect serves to maintain a pressurewithin the mold cavities 56, 58 optimal for curing of the foam and,hence, or formation of the earplug 10.

As a result of the densification of the foam at the vent passageways,the resulting earplug 10, as shown in FIGS. 2-4, includes foam formed atthe screw threads 62 or the knurls 64. That is, foam which cures in thevent passageways to form the effective seal of the mold 50 is removedfrom the mold 50 as a portion of the earplug 10. The foam at the screwthreads 62 or knurls 64 has a greater hardness and a higher density thanfoam formed at the insertable and handle portions 12 and 16,respectively.

In another embodiment, shown in FIGS. 14A and 14B, the mold upperportion 54 includes a screw vent portion 72 formed at the top end 66.The screw vent portion 72 includes screw threads 73 formed helically onthe mold upper portion 54 along a longitudinal axis of the upper cavity58.

During manufacture of the earplug 10, the component 14 of FIG. 13A isinserted in the upper mold portion 54 of FIG. 14B and retained thereinby the ribs 60. The component 14 contacts the screw threads 73 of thescrew vent portion 72 to form helical vent passages extending from theupper cavity 58 to the exterior of the mold upper portion 54. During thefoaming process, gas, particularly air originally disposed within thecavities, travels from the upper cavity 58 through the vent passages tothe exterior of the mold upper portion 54, similar to that describedabove with reference to the screw threads 64 formed on the component 14shown in FIG. 13B.

In another embodiment, shown in FIGS. 15A and 15B, the mold upperportion 54 includes a knurled vent portion 74 formed at the top end 66.The knurled vent portion 74 includes knurls 75 protruding into the moldupper cavity 58. During manufacture of the earplug 10 using thisembodiment of the mold upper portion 54, the component 14 of FIG. 13A isinserted in the cavity 58 and retained therein by the ribs 60 such thecomponent 14 contacts the knurls thus forming vent passagewaystherebetween. During the foaming process, gas, particularly airoriginally disposed within the cavities, travels from the upper cavity58 through the vent passages to the exterior of the mold upper portion,similar to that described above with reference to the knurls 68 formedon the component 14 shown in FIG. 13C.

In another embodiment, shown in FIGS. 16A and 16B, the mold upperportion 54 includes a flange vent portion 76 formed at the top end 66.The flange vent portion 76 includes annular flanges 77 formed on themold upper portion 54 about a longitudinal axis thereof and projectinginto the upper cavity 58. The flanges 77 include at least one spaceformed respectively therein. More preferably, the flanges include aplurality of spaces formed periodically across the annular distance ofthe flanges.

During manufacture of the earplug 10 using the mold upper portion 54having the flange vent portion 76, the component 14 of FIG. 13A isinserted in the cavity 58 and retained therein by the ribs 60 such thecomponent 14 contacts the flanges. Vent passageways are formed betweenthe component 14 and the mold upper portion 54 by communication of thespaces in the flanges 77. Accordingly, during the foaming process, gas,particularly air originally disposed within the cavities, is permittedto travel from the upper cavity 58 through the vent passages formed bythe communication of the annular tabs 77 and the upper mold portion 54to the exterior of the mold upper portion, thus allowing optimalproduction of the earplug 10.

The upper mold portion 54 including at least one of the screw ventportion 72, knurl vent portion 74, and flange vent portion 76, asmentioned, allows gas to travel from the mold cavities 56, 58 to theexterior of the mold 50. Specifically, during the foaming process, thefoam 53 rises within the cavities 56, 58 thus increasing the pressuretherein. This increased pressure forces air originally present withinthe cavities 56, 58 to travel through the vent passages to the exteriorof the mold 50. This venting allows proper rising and formation of thefoam 53.

Additionally, the upper mold portion 54 including at least one of thescrew vent portion 72, knurl vent portion 74, and flange vent portion76, prevents overflow of the rising foam material 53 to the exterior ofthe mold 50 thus preserving the integrity of the mold 50 and reducingwaste associated with the molding process.

Further, the upper mold portion 54 including at least one of the screwvent portion 72, knurl vent portion 74, and flange vent portion 76,allows a certain volume of the rising foam 53 to enter the ventpassageways and cure therein effectively sealing off the mold cavities56, 58 from the exterior of the mold 50. That is, after the excess airwithin the mold cavities 56, 58 is vented, the rising foam 53 ispermitted to fill the vent passageways and to cure therein. This sealingeffect serves to maintain a pressure within the mold cavities 56, 58which is optimal for curing of the foam and, hence, for formation of theearplug 10.

FIGS. 17A-17H show a method of manufacturing the earplug 10 using themold upper portion 54 including the screw vent portion 72.

In FIGS. 17A and 17B, the component 14 is inserted into the cavity 58 ofthe mold upper portion 54 and retained therein by ribs 60. The foam 53is disposed in the cavity 56 of the mold lower portion 52, as shown inFIG. 17C. The mold upper portion 54 with the component 14 inserted andretained therein is brought in proximity of the mold lower portion 52,as shown in FIG. 17D.

In FIGS. 17E and 17F, the cavities 56 and 58 are brought intocommunication, the component extending from the cavity 58 into thecavity 56. The foam 53 is then allowed and/or caused to rise throughoutthe cavities 56 and 58. In this way, a portion of the component 14exposed to the cavities 56 and 58 is completely encapsulated by the foam53. The foam 53 is then cured into a shape determined by the shape ofthe cavities 56, 58. During this process, the foam 53 forms a strongbond directly with the component 14.

During the foam rising process, gas within the mold cavities 56, 58 ispermitted to pass through the vent passageways formed between the screwvent portion 72 and the component 14 when the gas attains a certainpressure within the cavities 56, 58. This gas, as mentioned, is airoriginally disposed within the cavities 56, 58 and/or any gas that maybe evolved or otherwise present during the foaming process.

The screw threads 73 of the screw vent portion 72 prohibit the risingfoam material from spilling to the exterior of the mold 50. However, acertain amount of the rising foam material 53 is permitted to enter thevent passageways and to cure therein, sealing off the cavities 56, 58from the exterior of the mold 50, and thus maintaining a desiredpressure therein for curing of the foam and formation of the earplug 10.

Once the foam 53 has cured, the mold upper portion 54 is removed fromengagement with the mold lower portion 52, as shown in FIG. 17G. Thecomponent 14 remains retained in the mold upper portion by the ribs 60.The foam 53, now bonded with the component 14, leaves the cavity 56 ofthe mold lower portion 52.

Then, as shown in FIG. 17H, a tool 78 is used to eject the component 14with bonded foam 53 from the mold upper portion 54, thus completing themanufacturing of the earplug 10. Contact of the ribs 60 with thecomponent 14 during manufacturing of the earplug 10 results in theformation of the depressions 22 which may be shaped as desired byshaping or contouring the ribs 60 accordingly.

The earplug 10 is also similarly manufactured utilizing the mold upperportion 54 having the knurled vent portion 74 and utilizing the moldupper portion 54 having the flange vent portion 76.

In another embodiment, continuous manufacture of a plurality of theearplugs 10 is provided by moving the mold lower portions 52 under acontinuous pour machine which deposits a charge of the foam 53 in thecavities 53 and then engaging the mold upper portions with the moldlower portions to allow curing of the foam 53.

The invention, of which exemplary preferred embodiments are disclosedherein, provides a stemmed foam earplug that is effective in providinghearing protection, yet convenient and comfortable to use, and has amore efficient and lower cost method of manufacture. The earplugincludes a foam insertion portion encapsulating and bonded directly to acomponent stem; the foam insertion portion providing a comfortableportion for an insertion into a wearer's ear; the component stemproviding the necessary rigidity to facilitate proper insertion of theinsertion portion into the ear and/or providing a means for connecting acord, under the chin device, or headband component.

The method provided herein is particularly advantageous in that aneffective earplug is produced easily, efficiently, at low cost, andwithout the necessity of an additional bonding step. Furthermore, thebond formed according to the present invention is strong and durable,resulting in a dependable earplug having a long use life.

The costs for manufacture of the invention are lower than forconventional earplugs because the disposing of the foam around thecomponent eliminates the need for a separate bonding step, which wasotherwise required to adhere the component to the foam and, further,because costly porous component stems are not required due to thedisclosed venting means.

The venting means provided allows gas to escape from the cavities of therespective mold portions during the foaming process. The design of theventing means ensures that a desirable volume of gas escapes whilepreventing overflow of the foam from the cavities to the exterior of themold. Further, the venting means allows a certain volume of the risingfoam material to enter the vent passageways and to cure thereineffectively sealing off the mold cavities from the exterior of the moldthus maintaining a desired pressure in the cavities optimal for curingthe foam material and hence for forming the earplug.

The venting means allows utilization of simple, low cost component stemswhile ensuring consistent and optimal rising, curing, and bonding of thefoam to form the earplug.

In these ways, the invention is effective for providing low cost,reliable hearing protection to a wearer which is convenient andcomfortable to use.

While preferred embodiments have been shown and described, variousmodifications and substitutions may be made thereto without departingfrom the spirit and scope of the invention. Accordingly, it is to beunderstood that the present invention has been described by way ofillustrations and not limitation.

1. A method of making an earplug comprising: disposing a componentwithin a mold; introducing a foam or foamable mixture into said mold;and causing said foam or said foamable mixture to rise about saidcomponent such that said component is nested within and bonded with saidfoam, such that said component is at least partially within a foaminsertable portion and at least partially within a foam handle portion.2. The method of claim 1, wherein said foam or said foamable mixture isself-rising.
 3. The method of claim 1, wherein said foam is selectedfrom the group comprising polyurethane, acrylic, acrylic blends, andmixtures and combinations including at least one of the foregoingmaterials, and wherein said component is selected from the groupcomprising plastic, paper, dense paper, foam, porous foam, stiff foam,semi-stiff foam, cardboard, rubber, and combinations including at leastone of the foregoing materials.
 4. The method of claim 1, furthercomprising forming a depression in said foam along said component. 5.The method of claim 1, further comprising forming a passage in saidcomponent.
 6. The method of claim 1, further comprising venting the moldduring said causing said foam or foamable mixture to rise to allow a gasto move from an interior of the mold to an exterior of the mold.
 7. Themethod of claim 6, wherein said venting includes forming ventingpassageways between the component and the mold during said disposing ofthe component within the mold.
 8. The method of claim 7, wherein saidventing passageways extend from the interior to the exterior.
 9. Amethod of making an earplug comprising: disposing a component within amold; introducing a foam or foamable mixture into said mold; causingsaid foam or said foamable mixture to rise about said component suchthat said component is nested within and bonded with said foam, suchthat said component is at least partially within a foam insertableportion and at least partially within a foam handle portion; venting themold during said rising of the foam or foamable mixture to allow a gasto move from an interior of the mold to an exterior of the mold; andsealing said interior of said mold from said exterior after saidventing.
 10. A method of making an earplug comprising: disposing acomponent within a mold; introducing a foam or foamable mixture intosaid mold; causing said foam or said foamable mixture to rise about saidcomponent such that said component is nested within and bonded with saidfoam, such that said component is at least partially within a foaminsertable portion and at least partially within a foam handle portion;venting the mold during said rising of the foam or foamable mixture toallow a gas to move from an interior of the mold to an exterior of themold; and sealing said interior of said mold from said exterior aftersaid venting; wherein said sealing comprises allowing a volume of saidrising foam or foamable mixture to enter a vent used in said venting andcuring said volume therein.